In the old days, a
radio format was the way the station's program
director arranged the sequence of programming
elements to make up the day's schedule. After the
"golden age" of radio, when most
programming was provided by the big networks,
individual radio stations developed local
disc-jockey shows interrupted every half hour
with news. Over the years, formats have evolved
to the point where radio programming is carefully
designed to reach a specifically defined segment
or "niche" of the population, based on
such demographic criteria as age, income, ethnic
background, etc. A format may refer to the
overall programming (i.e. adult standards, news,
etc.) or the particular arrangement of
programming elements within a given hour.